JPH0740700Y2 - Variable capacity swash plate compressor swash plate - Google Patents

Description

[Technical Field] The present invention relates to a swash plate of a variable displacement swash plate compressor, and particularly, to change the tilt angle, the swash plate swing force and the strength of the swash plate that receive a control pressure described later. It concerns technology to secure.

(Prior Art) Generally, a variable displacement swash plate compressor employs a method of controlling a discharge capacity by changing a swash plate inclination angle according to a cooling load. For example, in the compressor disclosed in Japanese Patent Laid-Open No. 63-147977, the swing center when changing the swash plate tilt angle is set at the swash plate peripheral portion near one cylinder bore, and the swash plate rotates. The center position is variable. Then, the swash plate receives the control pressure applied to the control pressure chamber provided on the rear side and the swash plate swinging force generated by the pressure in the working chamber that opposes the control pressure chamber, and changes the tilt angle to a position where the two balance. A double-headed piston moored via a hemispherical shoe reciprocates with the top dead center of one cylinder bore being fixed at a fixed position, and the stroke is changed to change the discharge capacity.

Since the swash plate swings as described above, in order to keep the clearances of the swash plate, the hemispherical shoe, and the double-headed piston constant, a pair of hemispherical shoes arranged before and after the swash plate is sandwiched between the hemispherical shoes. It is configured to be a true sphere with a swash plate.

It is known that seizure is likely to occur if the parts of the swash plate, hemispherical shoe, and double-headed piston that contact each other are made of the same material. In consideration of weight reduction of the compressor itself, in the conventional swash plate type compressor, the swash plate and the double-headed piston are made of aluminum alloy, and the hemispherical shoe requiring hardness is made of iron-based metal. The plate and piston are made of different materials.

(Problems to be Solved by the Invention) As described above, the swash plate of the variable displacement swash plate compressor is configured to be a true sphere with the hemispherical shoes arranged in front of and behind it. For this reason, the hemispherical shoe cannot be made so large due to a space problem between the double-headed piston and the swash plate. Therefore, the hemispherical shoe is generally flat to some extent, and at the same time, the thickness of the swash plate is thin. Since the swash plate swings and receives the swash plate swinging force and the control pressure when the tilt angle is changed, the swash plate made of an aluminum alloy has a problem in strength. However, if an iron swash plate is used with an emphasis on strength, the same material as that of the hemispherical shoe is used, so that slidability is deteriorated and seizure may occur.

(Means for Solving the Problems) An object of the present invention is to provide a variable capacity swash plate compressor that solves the above-mentioned problems. The main body of the swash plate is made of an iron-based material, and the swash plate is A swash plate for a variable capacity swash plate compressor is proposed in which a layer of an aluminum alloy is integrally formed with the swash plate body on the peripheral portion of the main body.

(Operation of the Invention) The swash plate of the present invention configured as described above has a sufficient strength against control pressure and swash plate swinging force because the body is made of iron-based metal. A sliding contact is made with a hemispherical shoe made of an iron-based metal via an aluminum alloy layer formed on the peripheral portion of the swash plate body. Therefore, since the swash plate and the hemispherical shoe are in contact with each other as different materials, the slidability is also good.

(Example) The Example which actualized this invention is described based on drawing.
FIG. 1 shows a vertical sectional view of a variable displacement swash plate compressor. A front housing 3 in which suction chambers 25 and 26 and discharge chambers 27 and 28 are defined and formed on both front and rear end surfaces of the cylinder blocks 1 and 2.
And the rear housing 4 are attached, and partition plates 19 and 2 are provided between the cylinder blocks 1 and 2.
0, suction valves 21, 22 and discharge valves 23, 24 are provided.
Further, cylinder bores 1a and 2a and a swash plate chamber 6 are formed in the cylinder blocks 1 and 2, and the cylinder bores 1a and 2a of the partition plates 19 and 20 opened and closed by the suction valves 21 and 22 and the discharge valves 23 and 24, respectively. The suction chambers 25, 26 and the discharge chambers 27, 28 communicate with the suction chambers 25, 26 via the suction ports 19a, 20a and the discharge ports 19b, 20b. It is connected to 26. Then, a suction pipe line 32 that guides the refrigerant gas to the compressor is opened to the swash plate chamber 6, and the discharge chambers 27 and 28 are connected to the discharge pipe line 33 by the discharge passage 31.

The shaft 5 has a radial bearing on its front shaft portion 5a.
The rear shaft portion 5b is rotatably supported by the cylinder block 1 via a spool 13 and a slider 14 which will be described later.
It is supported by the cylinder block 2 via. A connecting portion 5c having a guide hole 5d is integrally formed between the front shaft portion 5a and the rear shaft portion 5b, and a thrust bearing 17 is interposed between the connecting portion 5c and the inner end of the cylinder block 1. Has been done.

The rear suction chamber 26 is provided with a bottomed cylindrical spool 13 having a flange portion 13a so as to be slidable forward and backward, and the flange portion 13a partitions a part of the suction chamber 26 into a control pressure chamber 26a. The cylindrical portion 13b of the spool 13 is inserted into the cylinder block 2, and a slider 14 is supported inside the cylindrical portion 13b via a radial bearing 16. The rear shaft portion 4b described above is slidably inserted into the slider 14. Also, the slider
A flange portion 14a and a spherical support portion 14b are integrally formed on the flange 14, and the flange portion 14a is supported on the end surface of the spool 13 via a thrust bearing 18, and the bridge 8 is integrated on the front surface of the spherical support portion 14b. The formed swash plate 7 is tiltably supported. Further, the above-mentioned connecting portion 5c and the bridge 8 are connected by the guide pin 9, and the guide pin 9 is connected to the swash plate 7.
It is possible to move inside the guide hole 5d at the same time when the tilt angle of the is changed. The main body 7a of the swash plate 7 is made of iron, and a layer 7b of aluminum alloy is cast-molded around the periphery of the main body 7a of the swash plate to be integrated with the main body 7a of the swash plate. Further, aluminum alloy double-headed pistons 10 reciprocally inserted into the cylinder bores 1a and 2a are anchored via iron hemispherical shoes 11 and 12 arranged on both front and rear surfaces of the swash plate 7. And the hemispherical shoes 11, 12 and the hemispherical shoes 11,
The swash plate 7 sandwiched between 12 forms a true sphere, and even when the inclination angle of the swash plate 7 is changed, the hemispherical shoes 11, 12 only rotate around a swing center C described later. The clearance between the shoes 11 and 12 and the double-headed piston 10 is kept constant.

In order to change the tilt angle of the swash plate 7, a capacity control valve mechanism 34 for adjusting the control pressure of the control pressure chamber 26a is installed outside the rear side of the compressor, and the capacity control valve mechanism 34 includes an inflow port 34a and an outflow port 34a. It has a port 34b and a control port 34c. The control pressure chamber 26a is connected to the inflow port 34a by the pipe line 37, the swash plate chamber 6 is connected to the outflow port 34b by the pipe line 39, and the suction pipe line 32 is connected to the control port 34c by the pipe line 40. A pipe line 38 having an open throttle portion 38a is connected to the rear discharge chamber 28, and the discharge chamber 28 and the control pressure chamber 26a are connected by the pipe lines 37, 38. Inflow port 34a and outflow port 3
The valve body 35 interposed between the control port and the spring 36 presses the valve body 35 in the opening direction and the total force of the spring 36 and the atmospheric pressure.
The opening and closing is driven by the pressure difference with the suction refrigerant gas pressure introduced from 34c, and when the valve body 35 is moved downward, that is, opened, the control pressure chamber
26a communicates with the swash plate chamber 6, and a part of the refrigerant gas corresponding to the discharge pressure in the control pressure chamber 26a flows into the swash plate chamber 6 according to the suction pressure.

The control pressure adjusted by the displacement control valve mechanism 34 presses the spool 13 toward the front side, and the slider 14 moving together with the spool 13 presses the swash plate 7 in the direction in which the inclination angle increases. On the other hand, the swash plate swinging force generated by the pressure in the working chamber formed by the cylinder bores 1a and 2a and the double-headed piston 10 acts in the direction in which the tilt angle of the swash plate 7 decreases, and opposes the control pressure together with the suction pressure. ing. Then, the tilt angle of the swash plate 7 is determined at a position where they are in balance with each other. Further, the swing center C of the swash plate 7 is set near the rear cylinder bore 2a in the peripheral portion of the swash plate 7, whereby the top dead center of the double-headed piston 10 is restricted to a fixed position on the rear side. As the tilt angle of the swash plate 7 changes, the stroke amount of the double-headed piston 10 becomes variable. Therefore, on the front side, the top dead center changes and the dead volume increases. Depending on the tilt angle of the swash plate 7, substantial compression and discharge are not performed, and expansion and compression are only repeated. Further, on the rear side, since the top dead center is unchanged, substantial compression and discharge are performed, but since the stroke amount of the double-headed piston 10 changes, the discharge capacity becomes variable. As described above, the control pressure is controlled by the capacity control valve mechanism 34 according to the cooling load, thereby changing the tilt angle of the swash plate 7 and making the discharge capacity of the compressor variable.

The operation of this embodiment configured as described above will be described. When an electromagnetic clutch (not shown) is connected and the rotational driving force of the engine is transmitted to the shaft 5, the swash plate 7 rotates together with the shaft 5. Since the swash plate 7 is inclined with respect to the shaft 5, its rotation is accompanied by rocking, and the swash plate 7 is rockingly rotated while slidingly contacting the hemispherical shoes 11, 12 made of iron, whereby the double-headed piston 10 is rotated. Reciprocates in the cylinder bores 1a and 2a.

The discharge capacity of the compressor is variably controlled by changing the tilt angle of the swash plate 7. That is, when the maximum discharge capacity is required, that is, when the cooling load is high, the pressure in the suction conduit 32 is high, and the pressure of the refrigerant gas introduced into the capacity control valve mechanism 34 is the sum of the spring 36 and the atmospheric pressure. Therefore, the valve element 35 is in the closed position and shuts off the control pressure chamber 26a and the swash plate chamber 6. Therefore, the refrigerant gas corresponding to the discharge pressure flows from the discharge chamber 28 into the control pressure chamber 26a, and a high pressure is applied to the spool 13 as the control pressure. Then, the control pressure presses the spool 13 and the slider 14 against the swash plate swinging force and the suction pressure, and the swash plate 7 increases the inclination angle until the guide pin 9 reaches the uppermost end of the guide hole 5d. The state of the maximum discharge capacity shown is obtained.

Further, when the cooling load decreases and the pressure in the suction conduit 32 decreases, the valve body 35 is opened by the spring 36 and the atmospheric pressure, and the control pressure chamber 26a and the swash plate chamber 6 communicate with each other. And the control pressure chamber 26a
A part of the refrigerant gas therein flows out to the swash plate chamber 6 according to the suction pressure, so that the control pressure decreases. Therefore, the tilt angle of the swash plate 7 is reduced by the swash plate rocking force, and the tilt angle of the swash plate 7 is determined at a position where the swash plate rocking force and the suction pressure balance with the control pressure.
When the minimum discharge capacity is required, the control pressure is further lowered, and the inclination angle of the swash plate 7 is decreased until the guide pin 9 reaches the lowermost end of the guide hole 5d, and the state of the minimum discharge capacity is obtained.

As described above, the swash plate 7 that changes the tilt angle according to the cooling load
Receives the control pressure and the swash plate swinging force that opposes the control pressure.
In particular, at the maximum discharge capacity, the force applied from both directions becomes the maximum, but the swash plate 7 in the present embodiment has its main body 7a.
Since it is made of iron, it has sufficient strength against the above-mentioned forces applied from both directions even if the wall thickness is thinner than before. Then, the layer 7b of the aluminum alloy formed by cast-molding on the swash plate main body 7a rotates while slidingly contacting the hemispherical shoes 11 and 12 made of iron, but since the layer 7b and the hemispherical shoes 11 and 12 are different materials, baking And there is no problem in slidability. Further, the aluminum alloy double-headed piston 10 that has been conventionally used can be used, and the weight reduction of the compressor is not significantly impaired.

The present invention is not limited to the above embodiment, and the aluminum alloy layers 7b may be pressure-bonded to the front and rear surfaces of the iron swash plate body 7a by a method such as friction welding. Also in this case, since the layer 7b and the iron hemisphere shoes 11 and 12 that are in sliding contact are made of different materials, the slidability is not impaired, and since the swash plate body 7a is made of iron, the strength is the same as in the previous embodiment. Is also sufficient.

(Effect of the Invention) As described in detail above, since the swash plate of the variable capacity type swash plate compressor of the present invention is made of iron, it is sufficient for the swash plate rocking force and control pressure received from both front and rear surfaces of the swash plate. The iron-based hemispherical shoe, which has strength and is interposed between the swash plate and the aluminum alloy double-headed piston, does not impair the slidability because the layer formed of the aluminum alloy makes sliding contact and seizure occurs. There is no fear of doing it. Therefore, although a swash plate thinner than before is used, the reliability of the compressor is not impaired.

[Brief description of drawings]

The accompanying drawings show an embodiment embodying the present invention, and FIG. 1 is a vertical sectional view of a variable capacity type swash plate compressor. Cylinder block 1, 2 Shaft 5 Swash plate chamber 6 Swash plate 7 Iron swash plate body 7 Aluminum alloy layer 7b Aluminum alloy double-ended piston 11 Iron hemisphere shoe 11, 12

Claims (1)

[Scope of utility model registration request] 1. A shaft rotatably supported in a cylinder block supports a swash plate such that the shaft is relatively non-rotatable and can swing in the front-rear direction, and the swash plate is supported by a pair of ferrous material hemispherical shoes through which aluminum is mounted. An alloy double-headed piston is moored, the hemispherical shoe forms a true sphere with a swash plate sandwiched between hemispherical shoes, and the rotation of the shaft is converted into reciprocating motion of the piston by the swash plate, while In a variable capacity type swash plate compressor in which the stroke of the swash plate is changed by changing the inclination angle of the swash plate, the main body of the swash plate is formed of an iron-based material, and an aluminum alloy layer is formed on the peripheral portion of the swash plate main body. Is formed integrally with the swash plate body, and the swash plate of the variable capacity type swash plate compressor is characterized in that